796 research outputs found

    Nematicidal and allelopathic responses of Lantana camara root extract

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    The impact of root leachates of Lantana camara L., a tropical weed, against Meloidogyne javanica, the root-knot nematode, was tested under laboratory and pot conditions. Concentrated and diluted root leachate caused substantial mortality of M. javanica juveniles. Significant suppression of the nematode was achieved when soil was treated with a full-strength concentration of the leachate. Whilst this high concentration retarded plant height and shoot fresh weight, more diluted concentrations actually enhanced plant growth. To establish whether this inhibition of plant growth from the leachate was the result of depleted nitrogen levels in the soil due to the leachate, soil treated with such leachates was given urea as an additional nitrogen source. Urea not only enhanced nematode suppression activity of the root leachates but also increased seedling emergence and growth of mungbean. Application of the L. camara root leachates in combination with Pseudomonas aeruginosa, a plant growth-promoting rhizobacterium, significantly reduced nematode population densities in roots and subsequent root-knot infection, and enhanced plant growth. While a high concentration of root leachate slightly reduced P. aeruginosa colonization in the rhizosphere and inner root tissues, the nematicidal efficacy of the bacterium was unaffected. The root leachate of L. camara was found to contain phenolic compounds, including p-hydroxybenzoic acid, vanillic acid, caffeic acid, ferulic acid and a quercetin glycoside, 7-glucoside. It also contained weak enzymic hydrogen cyanide

    Massless BTZ black holes in minisuperspace

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    We study aspects of the propagation of strings on BTZ black holes. After performing a careful analysis of the global spacetime structure of generic BTZ black holes, and its relation to the geometry of the SL(2,R) group manifold, we focus on the simplest case of the massless BTZ black hole. We study the SL(2,R) Wess-Zumino-Witten model in the worldsheet minisuperspace limit, taking into account special features associated to the Lorentzian signature of spacetime. We analyse the two- and three-point functions in the pointparticle limit. To lay bare the underlying group structure of the correlation functions, we derive new results on Clebsch-Gordan coefficients for SL(2,R) in a parabolic basis. We comment on the application of our results to string theory in singular time-dependent orbifolds, and to a Lorentzian version of the AdS/CFT correspondence.Comment: 28 pages, v2: reference adde

    Comparative evaluation of in vitro cytotoxic effects among parent abietyl alcohol and novel fatty acid ester derivatives against MCF7 and hepatocellular carcinoma cell lines

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    Synthesis of twelve hitherto unreported esters of abietyl alcohol and screening of these esters against four cancer cell lines including one breast cancer line MCF7 and four hepatocellular carcinoma cell lines (HCC) Huh7, Hep3B, Snu449 and Plc has been determined using SRB assay. The Cell cycle progression showed changes in cellular behaviour after 48 and 72 hours in MCF7 and Huh7 cell lines. Abietyl alcohol was obtained from the reduction of abietic acid, a tricyclic diterpene, isolated from oleoresin of Pinus longifolia Roxberghii

    Eye Tracking-Based Diagnosis and Early Detection of Autism Spectrum Disorder Using Machine Learning and Deep Learning Techniques

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    Eye tracking is a useful technique for detecting autism spectrum disorder (ASD). One of the most important aspects of good learning is the ability to have atypical visual attention. The eye-tracking technique provides useful information about children’s visual behaviour for early and accurate diagnosis. It works by scanning the paths of the eyes to extract a sequence of eye projection points on the image to analyse the behaviour of children with autism. In this study, three artificial-intelligence techniques were developed, namely, machine learning, deep learning, and a hybrid technique between them, for early diagnosis of autism. The first technique, neural networks [feedforward neural networks (FFNNs) and artificial neural networks (ANNs)], is based on feature classification extracted by a hybrid method between local binary pattern (LBP) and grey level co-occurrence matrix (GLCM) algorithms. This technique achieved a high accuracy of 99.8% for FFNNs and ANNs. The second technique used a pre-trained convolutional neural network (CNN) model, such as GoogleNet and ResNet-18, on the basis of deep feature map extraction. The GoogleNet and ResNet-18 models achieved high performances of 93.6% and 97.6%, respectively. The third technique used the hybrid method between deep learning (GoogleNet and ResNet-18) and machine learning (SVM), called GoogleNet + SVM and ResNet-18 + SVM. This technique depends on two blocks. The first block used CNN to extract deep feature maps, whilst the second block used SVM to classify the features extracted from the first block. This technique proved its high diagnostic ability, achieving accuracies of 95.5% and 94.5% for GoogleNet + SVM and ResNet-18 + SVM, respectively

    Translational invariance of the Einstein-Cartan action in any dimension

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    We demonstrate that from the first order formulation of the Einstein-Cartan action it is possible to derive the basic differential identity that leads to translational invariance of the action in the tangent space. The transformations of fields is written explicitly for both the first and second order formulations and the group properties of transformations are studied. This, combined with the preliminary results from the Hamiltonian formulation (arXiv:0907.1553 [gr-qc]), allows us to conclude that without any modification, the Einstein-Cartan action in any dimension higher than two possesses not only rotational invariance but also a form of \textit{translational invariance in the tangent space}. We argue that \textit{not} only a complete Hamiltonian analysis can unambiguously give an answer to the question of what a gauge symmetry is, but also the pure Lagrangian methods allow us to find the same gauge symmetry from the \textit{basic} differential identities.Comment: 25 pages, new Section on group properties of transformations is added, references are added. This version will appear in General Relativity and Gravitatio

    Step and Step-Nc as a Tool for Big Data in Cloud Manufacturing

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    The terms big data, cloud manufacturing, predictive and additive manufacturing, and Internet of Things (IoT) are being most commonly used in the manufacturing industry nowadays. These terms are related to the fourth industrial revolution that emphasizes automation and data exchange between manufacturing tools/elements. Communication occurs between machines, products and even technicians or operators through various technologies while creating records of each interaction resulting in rapid growth of amount of data to be stored. Data acquisition is not a major issue since a structure or framework can properly connect these data in improving manufacturing efficiency. However, lack of effort in collecting and storing manufacturing data in the whole product life cycle process has made integration to be almost difficult to achieve. In this study, the adoption of STEP-NC method/technique was demonstrated in suiting the current explosion of big data in the industrial and manufacturing sector. The proposed methodology was developed through a study of an entity file structure and hierarchical concept in STEP and STEP-NC in gathering manufacturing data in a unified database. The challenge would be in making sense of the data, revealing the patterns in it and using them for operational improvements. The outcome of this study will be useful to support strategic decision making in product manufacturing

    Clonal structure of Ceratocystis manginecans populations from mango wilt disease in Oman and Pakistan

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    Ceratocystis manginecans has recently been described from Oman and Pakistan where the fungus causes a serious wilt disease of mango. In both countries, the disease has moved rapidly throughout mango producing areas leading to the mortality of thousands of mango trees. The disease is associated with the infestation of the wood-boring beetle Hypocryphalus mangiferae that consistently carries C. manginecans. The aim of this study was to consider the population structure of C. manginecans isolated from Oman and Pakistan using microsatellite markers and amplified fragment length polymorphisms (AFLPs).Population genetic analysis of C. manginecans isolates from diseased mango tissue and bark beetles associated with the disease in Oman and Pakistan, showed no genetic diversity. The apparently clonal nature of the population suggests strongly that C. manginecans was introduced into these countries as a single event or from another clonal source.Tree Protection Co-operative Programme (TPCP), National Research Foundation (NRF), South Africa and the Ministry of Agriculture and Fisheries in Sultanate of Oman.http://link.springer.com/journal/13313hb201
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